He doesn't know how to get in touch with others, so that he can only rely on cold jokes to ease the embarrassment and tension in an environment every time. Joey is sincere and belongs to the silly sweet department. Compared with Ross, he will be happy when he is happy and will not hide his emotions when he is sad. His "innocence" and Chandler's personality complement each other and fill the vacancy in Chandler's heart. During the time when Joey had no money, Chandler contracted rent and even water and electricity alone, and also solved some meals for Joey. He didn't say anything when he borrowed money.
Another feature of Joey is that he hardly shares his things with others, but there is one exception, and that is Chandler. When Joey made money, he wanted to move out and live alone. He doesn't have that much concern, just wants to try what life is like alone. When Chandler found out, they were very unhappy. But after all, he didn't stand up and keep Joey directly. After the separation, Chandler always felt that something was missing at home, and Joey was unhappy.
When all my friends went to see Joey's new house, only Chandler didn't go. Joey's mood was empty when Chandler didn't come. Later, when Joey got a roommate, Chandler felt that his friend had been robbed and was unhappy. Both of them are in each other's area, but they often miss each other. Therefore, their lives have been completely integrated into each other. So when Chandler and Monica imagined their married life, Joey was alone. Chandler said that he would build a house and leave a room for Joey to spend his old age.